Rectifier control system



April 30, 1935.. GAUDENZI 1,999,755

RECTIFIER CONTROL SYSTEM Filed Nov. 4, 1932 Patented Apr. 30, 193$ i UNITED STATES PATENT OFFICE RECTIFIER CONTROL SYSTEM Arthur Gaudenzi, Baden, Switzerland, assignor to Aktiengesellschaft Brown Boveri & Cie., Baden, Switzerland, a joint-stock company of Switzerland Application November 4, 1932, Serial No. 641,148 I In Germany November 25, 1931 10 Claims. (01. 175-363) This invention relates to improvements in recthe How of current through an anode may be intifier control systems and more particularlyto itiated by means other than the control elecmeans for controlling the moment at which the trodes associated therewith. anodes of an electron discharge device of the Another object of the present invention is to gaseous or of the vapor type start carrying curprovide a control system for electron discharge 5 rent during each cycle of the supply line. 7 d vi s f s s r f h vap r p n Wh h It is well known that, in an electron discharge the flow of current through an anode may be device, each anode may carry current only when ni ia ed by m m y energization of 'Sneh such anode is at a positive potential with respect an d at a Vo tag h h a the normal Oper- 10 to the cathodepotential. Such flow of current ating voltage thereof. 10 may be prevented by maintaining a, itabl Another object of the present invention is to trol electrode ata potential belowaso-called critiprovid a nt l s s m for electron dis ha cal Voltage which is generally approximately the devices of gaseous or of the vapor typ in which cathode potential, such flow of r t the anodes of the device may sequentially receive however, occur when the potential of the control control Voltages through auxiliary electron d s-'16 electrode is not below such critical voltage and Charge v is variable dependent upon the conditions of Objects n v n a s th r than those above pressure, of temperature within the device and Set forth Will be pp from the fOlIOWing d upon the instantaneous voltage of, the associated ecripiiien When read in Connection w th the ac an anode, and such action is frequently disturbed by companyin rawin whi di r mm i ly 1'1- the occurrence of s -call d ba k fires during lustrates one embodiment of the present inven- Which then operates as an anode. In addition, rectifier may be q t y e ed at 0011- the current flowing through a control electrode o potentials through a plurality f a y 25 of the control electrode may easily differ by conillustrated as a i' Phase line for th reason 30 thereto by the source. The above disadvantages in practice. -Line 6 energizes the delta connected are particularly objectionable in direct current primary Winding 0f a transformer av a inverting systems in which the sequence of enerc a y Winding 3 Comprising a p a ity f gization of the control electrodes must be very Portions Such as 311 inier-eom'leetedin Star form 35 accurate to secure proper operation of the system. a u a P Transformer 3 ay a b Such disadvantages may be obviated by main p ovidedw h a s p e e y w d 9 t e taining the control electrodes at such potential p p f which Will appeal hereinafter- The that no flow of current may occur from the difier nt po ti s o W din 8 are severally con- 40 anodes of the device when such anodes are enneeted t r u h a; plurality of reactors S as N 40 ergized at their normal operating voltages. Such Wi h a d Such as Of an electron discharge flow of current may then be initiated by momendevice 13 having a cathode l4. Electron discharge tarily increasing the potential of each anode to device I3 is herein shown as being of the metallic such a value that the associated control elec- Vapo arcing p n is assumed to be p ded trode becomes inactive. V with the usual ignition and excitation means (not 45 It is therefore among the objects of the res. shown). Device I 3 is assumed in the present disent. invention to provide" a control; system for closure to be operable as an electric current rectielectron discharge devices of the gaseous or of fier and cathode l4 thereof is therefore connectthe vapor type in which the flow of current ed with the positive conductor l6 of a direct ourthrough an anode cannot occur upon energization rent output circuit having the negative conductor 50 of such anode at the normal operating voltage I? thereof connected with the neutral point of thereof. V winding 8. -Rectifier I3 is provided with a plu- Another object of the present invention is to rality of control electrodes such as l8 which are provide a control system for electron discharge severally energized through resistance such as 2! devices of gaseous or of the-vaportype in which from a battery I 9 connected with cathode M of 5' 3?; the rectifier. The construction of the control electrodes is assumed to be such that, when such control electrodes are energized from battery l9, current may not fiow through the anodes of the rectifier when such anodes are energized at their operating voltages but may flow when such anodes momentarily receive a voltage which is considerably higher than the normal operating peak voltage thereof.

Each anode such as i2 is connected with the cathode 22 of an electron discharge device 23 having a control electrode 24 and an anode 26. Device 23 is herein illustrated as being of the hot cathode type having a cathodic filament heated by means of current drawn from a suitable source such as one of the portions of winding 9. Anode 26 is connected with cathode M of the rectifier through the secondary winding 21 of a transformer having a primary winding 28 energized from line 5 through an adjustable condenser 29 and an adjustable reactor 31. Control electrode 2 of the device is connected with cathode 22 thereof through the secondary winding 32 of another transformer having a primary winding 33 energized from line 6 through an adjustable condenser ?i i and an adjustable reactor 36. It will be understood that members H and 21 to 36 inclusive will be required in numbers equal to the number of anodes of rectifier l3, such number being six in the present embodiment, but that only one of each of such members are illustrated in the drawing for the purpose of simplifying the drawing. The plurality of transformers 21, 28 and 32, 33 as a whole must receive six phase currents from line 6 and, as such line is a three phase line, six phase currents may be obtained therefrom by utilizing each pair of conductors twice, but applying the identical voltages thus obtained in reverse connections.

In operation, assuming the system to be connected as shown in the drawing and line 6 being energized, winding 1 is energized from line 6 with the result that winding 8 impresses six phase potentials on the several anodes of rectifier l3. Winding 9 energizes the filaments 22 of devices 23 which are therefore operable as electric current rectifiers. As already stated above, it is assumed that, when the control electrodes of rectifier 13 are energized from battery 19 and the anodes of the rectifiers are energized at their normal operating voltages from winding 8, no current may fiow through the rectifier. Assuming that, at the instant considered, anode l2 is at a positive potential with respect to cathode l4 and that at such instant it is desired to initiate the flow of current through such anode, reactor 3| and condenser 29 are so adjusted that winding 21 impresses, between anode Zfi of device 23 and cathode I4 of the rectifier, a voltage considerably in excess of the positive voltage of winding portion 8a. Reactor 3% and condenser 3 are then soadjusted that, at the instant considered, control electrode 24 is brought to such potential as to permit fiow of current between anode 26 and cathode 22 of device 23. The voltage of winding 21 is thus impressed between anode l2 and cathode 14 of rectifier 43 in an open circuit over anode 26 and cathode 22 of device 23. Such voltage is also impressed on a closed circuit comprising reactor H, winding portion 8a, conductor H, the load connected therewith (not shown) and conductor IE but, due to the presence of reactor H, such voltage remains impressed at substantially the full value thereof between anode l2 and cathode H for a sufficient period of time to permit initiation of the fiow of current from anode 12 to cathode l4. Current then fiows from winding portion 811 over reactor ll, anode l2, cathode l4, conductors l8 and H to the neutral point of winding 8 as is well known in the art; such flow of current continuing as long as anode I2 is positive with respect to cathode Id and is no longer influenced by the presence of control electrode l8 or by the potential of winding 21. During such flow of current, winding 21 is short circuited over device 23 and rectifier 13 thus causing the entire voltage of line 6 to appear across condenser 29 and reactor 31 which cooperate to limit the current flowing through winding 28. Such cycle of energization is repeated sequentially for each anode of rectifier I3 during each cycle of the voltage of line 6 to permit the flow of a substantially uniform current to the output circuit of rectifier l3.

The moment of the voltage cycle of line 6 at which flow of currentis initiated in anode l2 may be varied by varying the adjustment of condenser 34 or of reactor 36. Thereby also regulating the average voltage of the output circuit and the amount of current flowing therethrough.

Although but one embodiment ofthe present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed Patent:

1. In a control system for an electron discharge device, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes, a transformer connecting said and desired to secure by Letters line with the anodes of said device, static means severally associated with the anodes to prevent operation thereof, and an electron discharge device associated with each of the anodes of the first said device to cause operation thereof during portions of the potential cycle in said line, the last said device being connected with the anodes and with the cathode of the first said device and with said line.

2. In a control system for an electron discharge device, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes and a cathode, a transformer connecting said line with the anodes of said device, static means severally associated with the anodes to prevent operation thereof, an electron discharge device associated with each of the anodes of the first said device to cause operation thereof during portions of the potential cycle in said line, the last said device being connected with the anodes and with the cathode of the first said device, and means connecting the last said devices with said line to cause phase displacement of the potential applied thereto relative to the potential applied to the first said device.

3. In a control system for an electron discharge device, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes and a cathode, a transformer connecting said line with the anodes of said device, static means severally associated with the anodes to prevent operation thereof, an electron discharge device associated with each of the anodes of the first said device to cause operation thereof during portions of the potential cycle in said line, the last said devices beingconnected with the anodes and with the cathode 0! the first said device, condensers connected with each of the last said devices, and a reactor connecting each of said condensers with said line, said condensers and said reactors being variable to permit variation of the phase of the the phase of the potential applied to the first said device from said line.

4. In a control system for an electron discharge devlce, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes and a cathode, a transformer connecting said line with the anodes of said device, static means severally associated with the anodes to prevent operation thereof, and electron discharge devices each having an anode connected with the cathode of the first said device and a cathode connected with an anode of the first said device and a control electrode connected with said line, the last said devices being arranged to cause operation of the anodes of the first said device only during portions of the potential cycle in said line.

5. In a control system for an electron discharge device, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes each with an associated control electrode and having a cathode, a transformer connecting said line with the anodes of said device, a source of potential connected with said line to cause phase displacement of the potential applied to the last said device relative to the potential applied to the first said device.

6. In a control system for an vice, static means severally associated with the anodes to prevent operation thereof, electron discharge devices each having an anode connected with the cathode of the first said device and a cathode connected with an anode of the first said device and a control electrode connected with said line, and means severally connecting the anodes and the control electrodes of the last said devices with said line to cause operation of the anodes of the first said device only during portions of the potential cycle in said line.

7. In a control system for an electron discharge device, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes and a cathode, a transformer connecting said line with the anodes of said device, static means severally associated with the anodes to prevent operation thereof, electron discharge devices each having an anode connected with the cathode of the first said device and a control electrode connected with said line, transformers connected with the anodes and the control electrodes of the last said devices, and means connecting said transformers with said line to cause phase displacement of the potential applied to said transformers relative to the potential applied to the first said device.

8. In a control system for an electron discharge device, an alternating current line, an electron discharge device of the vapor type having a plurality of anodes and a cathode, a transformer connecting said line with the anodes of said device, said transformer having a tertiary winding, means comprising a source of current connected with said cathode and with said control electrodes for applying thereto a potential negative relative to the potential of said cathode, an electron discharge device associated with each of the anodes of the first said device and having a cathode connected with the tertiary winding of said transformer to cause electron discharge and variable means connecting the anodes and the control electrodes of the last said devices with said line to cause phase displacement of the potential applied thereto relative to the potential applied to the first said device.

9. In a control system for an electron discharge device, an alternating current line, an electron discharge device having anodes with associated control electrodes and a cathode, the anodes being connected with said line, a source of potential negative relative to the potential of the cathode of said device, the control electrodes of said device being continuously connected with said source to prevent operation of the anodes thereof at the operating potentials applied thereto from said line, and means for sequentially impressing potential surges on the anodes of said device higher than the operating potentials thereof to cause flow of current therethroug 10. In a control system, in combination with an electric current supply circuit, an electric current load circuit, and an electron discharge device comprising a cathode and an anodeinterof either of said circuits, and means connected with said anode and impressing thereon potential of such sign and magnitude and during such moments as to initiate said arcs, the potential of said supply circuit being of such magnitude as to maintain said arcs.

ARTHUR GAUDENZI. 

